low latency tuning of RHEL 7 - main things to do?

I'm using my server for HFT trading. I'm using HP guide for tuning http://h10032.www1.hp.com/ctg/Manual/c01804533.pdf
Unfortunately this guide still not updated for RHEL 7, but I've tried to follow it (hoping that things not changed).

Guide suggests:
"Edit /boot/grub/grub.conf and add "nosoftlockup intel_idle.max_cstate=0 mce=ignore_ce" to the kernel line"
In RHEL 7 i have "/boot/grub2/grub.cfg", but it starts with "DO NOT EDIT THIS FILE". So to achive the same effect on RHEL 7 what should I do? Or I should ignore ""DO NOT EDIT THIS FILE" warning?

Where and how should I set this? "Edit /boot/grub/grub.conf and add "idle=poll" to the kernel line". Or, again, I should ignore ""DO NOT EDIT THIS FILE" warning?

(Probably you can suggest something else for low-latency. So far I executed "tuned-adm select network-latency" - this helped a lot. Also I stopped many services and followed Solarflare guide.)